Next up some remarks on focus:
- the travel of the focus ring is huge: >180° for a non-macro lens - for a full run the motor needs about 3/4 of a second (not scientifically measured). That's surely not the fastest - as already mentioned: sometimes focus is just off. Check your photos for critical sharpness! - play in the gear is minimal (much better as in my AF 85/1.8!) - focussing from infinity or 45cm yields almost identical results

@Graham: It's still 45cm at the closest And IQ is visibly deteriorating that close. So stop the lens down to at least f/5.6 if you want any decent close-up IQ!
@pgtips: No hunting has haunted me yet. But perhaps I didn't try it dark enough

@pgtips: As this is not a macro lens it is not specifically corrected for close-ups. That's also the reason why Nikon limited the closest focus-distance. So even if you could use extension-tubes, don't try it!

I got mine yesterday. I have had problems with the AF of my S5 and by what I have read in various fourms around the world, the conclusion I drew myself seems to be right: it has problems with several older, non AF-S lenses as well as with some lenses from 3rd party manufactures. I never had problems with genuine Nikkor AF-S lenses.

So I was a bit surprised to see some randomness in focus accuracy with the new 50mm. My AF-D 50mm F1.8, albeit beeing a non af-s lens, was very sure in that regard. I am somehow reliefed that this issue isn't dedicated to the S5, so the rule of having no body-caused problems with AF-S lenses persists.

I still have to validate the effects in real life photos. A perfect oportunity will arise on friday when my cam and the new 50mm will be given in the hands of a friend of mine which isn't very skilled in camera operation but needs a light efficient prime lens & cam combination for a theatre performance. I'll have a closer look into the results.

BTW, this body AF problem was the reason I put the telezoom story on hold. The Tamron AF inconsistence might have been a problem of the S5, as well as the inconsistence of the AF-D 80-200mm I tested later on (which whould have been a keeper otherwise). The only obvious solution in this regard seems to be the AF-S VR 70-200mm which is over my budget. I hope to get a good deal once the new version appears on the market. Until then, I'll return to my principle of using primes whenever a proper version exists.

Interesting observation, Christian! I'll come to focus-consistence after I've shot more. In the testcharts the delta between focussing on a target with the lens coming from infinity vs coming from 45cm seems minimal, but still can cause some color shift from redish to greenish bokeh at f/1.4 as this lens has longitudinal CAs (not too bad in my opinion).
But shooting on a three-dimensional subject like a tree you have to be very careful to understand where the AF-system thinks the least phase-shift is

@Alex: I'll definitely keep this lens!
@pgtips: This early morning I was runnning around in a cold and foggy dawn with EVs around 1/30 sec, f/1.4, ISO 640. I did not observe any hunting from the lens. With the close-up IQ I cannot prove it as my testchart doesn't have enough resolution for testing around or beyond 1:10.

Now here's one captured this cold and gray December morning. At 1/45 sec (handheld!), f/1.4 (!), ISO 200, -1EV, picture-mode=vivid, focus=AF. Post-processing: cropping and some curves. I've converted this to jpg unsing CaptureNX2 and saved it with highest quality setting in full resolution. Just click through the image to delve into every single pixel this lens could throw on the D300 sensor - which still has a higher pixel densitiy than the fabulous new D3x